The ring is built on the existing nitrogen atom of the nitro group, and employs a chain connected to the ortho position of the arene. The latter can be a side chain existing in the substrate, or can be formed in the addition reaction of appropriate nucleophile to the nitroarene, with formation of s H adduct in the ortho position. Thus, two ways of the reaction course can be formulated, and are depicted in Scheme [¹] . ... The starting materials for the described syntheses are not ...
